Just because Homura doesn't age naturally doesn't mean she can't necessarily age unnaturally. She managed to manipulate her fleshly shell to fix her eyesight, after all.
And so long as she would have to interact with normal mortals at all (and in particular Tatsuya), she'd have to appear to age, so people wouldn't get suspicious about the eternal middle-schooler.
Didn't Madoka change the ruling on the whole magical girl contracts when she became a goddess? I would imagine the girls would no longer have their souls removed since one of major reasons for doing it in the first place doesn't exist. Evidence of this can be seen in the final episode when Homura was feeding Kyuubee the small black boxes.
Nope, all she did was remove their transformation into witches out of grief. To the rest of the world, her actions just make it look like the soul gems simply disappear, but nothing else has changed.
According to production notes Roberta was a magical girl for a long time and thus in her 20's to 30's when she became a Witch, so I think they do age normally. Homu probably used her magic power to control her age.
Anonymous9000 said: According to production notes Roberta was a magical girl for a long time and thus in her 20's to 30's when she became a Witch, so I think they do age normally. Homu probably used her magic power to control her age.
That doesnt mean they age, just that the magical girl lived for a long time.